1993 Fiscal Year Final Research Report Summary
Nondestructive Measurement of Stress and Material Properties using Electromagnetic Fields
| Project/Area Number |
04650084
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| Research Category |
Grant-in-Aid for General Scientific Research (C)
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| Allocation Type | Single-year Grants |
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| Research Field |
材料力学
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| Research Institution | KYOTO UNIVERSITY |
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Principal Investigator |
MATSUMOTO Eiji Kyoto University, Faculty of Engineering, Asocc.Professor, 工学部, 助教授 (30093313)
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| Co-Investigator(Kenkyū-buntansha) |
MOTOGI Shinya Osaka City University, Faculty of Engineering, Asocc.Professor, 工学部, 助教授 (40221626)
SHIBATA Toshinobu Kyoto University, Faculty of Engineering, Professor, 工学部, 教授 (40025929)
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| Project Period (FY) |
1992 – 1993
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| Keywords | Acoustoelasticity / Magnetoacoustoelasticity / Stress Measurements / Nondestructive Evaluation / Magnetic Materials / Ultrasonic Waves / Magnetoelasticity / Magnetostriction |
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| Research Abstract |
The main purpose of the research was to develop magnetoacoustoelasticity proposed by the investigators, and to achieve more practical nondestructive techniques of stress evaluation and a new technique available for nonmagnetic materials.
1. Establishment of nonlinear electromagnetoelastic constitutive equations and their verification
We proposed the constitutive equations of nonlinear ferromagnetic materials with hysteresis and theoretically analyzed the effects of magnetic hysteresis on the propagation of ultrasonic waves. We also proposed the constitutive equations of plastic ferromagnetic materials and proved that we can separate the effects of the plastic deformation and the magnetoelastic couplings on the speed shift of ultrasonic waves. From the result, it becomes possible to apply the magnetoacoutoelasticity to materials subjected to larger stresses. In order to take into account wider classes of materials and deformations, we proposed the magnetic constitutive equations which can describe the effects of magnetic rate and anisotropy.
2. Nondestructive evaluation of stress and material property under magnetic field
We showed that from the speed shift of ultrasonic waves under the magnetic field, it becomes possible to separate the texture and the stress anisotropies and to evaluate more accurate stress which has been difficult by conventional techniques. We further examined that by applying the magnetic fields to the specimen, the plane stress can be evaluated by measuring the speed shift of one kind of ultrasonic wave. We examined that the distribution of the material density or the elastic constants can be obtained from that of the wave speed for sintered materials.
3. Extension of magnetoacoutoelasticity
We generalized magnetoacoutoelasticity to noumagnetic materials by using the piezoelectric or electrostrictive effects. Verification of the theoretical study by experiments has not been done and left for the future subject.
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Research Products
(14 results)
